Question is, is that something you recognize, or something that you've had confirmed by others? It's easy for an author to see what's there when they right, and because of that understate it and wind up not showing it well enough. If this is a consistent complaint, it's wholly possible you're just not getting the real nature of their relationship across.
Obviously I've not read it, so I can't say for sure. And I mean given the subject matter it's more than likely a few people are going to be critical from premise alone, because you have to admit whether or not it is a slavery thing, the way the concept looks...
Now, to be fair to this critic, I intentionally make some aspects of their relationship ambiguous because Surprise and Raydence are
supposed to be confusing and "WTF?" on a certain level and if I made them too squeaky-clean, she wouldn't live up to her name. So yes, I can see how she sometimes looks like a crack-brained slavedriver.
But I think that there's also enough leeway to say that when Surprise makes angry rants or gestures at Raydence or attempts to "punish" him, its clearly an act. For example in the Diamond Dog story where
Surprise directly says that she never wanted to marry King Dowazer, which means her and Raydence's fight earlier—which is the whole reason she broke off the engagement—must've been an act.
Guy also says that Raydence never shows free will, which is point-blank false.